My BEST Science Activity

 

Title:  Egg-speriment With A Cell

Teacher:  Betty Jo Leonard/Prentice Hall             

Grade Level:  7th Grade

Objective:  Students will be able to see a model of how a cell membrane

works to let water enter and leave the cell.

 

 

 

 

 

SUPPLIES NEEDED FOR EACH GROUP OF 4 STUDENTS

 

1 Chicken egg

1 Plastic container with lid (small recycled container), 0.47mL (pint size)

1 0.35 mL of the following solutions

          White Vinegar

          Tap water

          Food Coloring (different colors)

          Salt

          Clear carbonated beverage

          Dark carbonated beverage

          Colored carbonated beverage (ask a bottling company for donations)

Plastic dishpans or buckets if sinks are not available

Paper Towels (10)

Cooking twine (2.54 centimeters)

Large bucket for waste water if sinks are not available (the cafeteria

 usually has extras)

          Graph Paper

Coloring Pencils

Measuring tape (flexible)

 

EXPERIMENT

 

  1. Students will use a chicken egg.

 

  1. Students will observe and record their findings each day in their Lab Journal.

 

  1. Students will make and record observations about their eggs before they actually start the experiment.
    1. appearance
    2. size
    3. shape
    4. color
    5. texture
    6. measure the circumference [hold the egg horizontally and measure at the equator (center)] of the egg (use the procedure on the following page)

 

  1. Students will soak the egg in various solutions for a minimum time of two days.

 

  1. The egg will be rinsed and patted with a paper towel dry between each solution. 

 

  1. Students will do an observation each day and record their observation (those listed in # 3 and any others) in their Lab Journal (use the table on the following page).

 

  1. It is very important that students’ measure and record the circumference each day (remind students that they are to use centimeters when measuring).

 

  1. Graph the data that has been collected and prepare a report with the results.

 

PROCEDURES: 

 

  1. After students have soaked the egg in vinegar for at least two days (exposing the membrane), students will observe the size of the egg as changes occur, using various solutions, allowing the egg to gain or lose water through the membrane.

 

  1. Rinse off the egg and pat with a paper towel being careful not to drop the

egg.

 

  1. Measure the circumference of the egg (instructions to follow at the end of the experiment).

 

  1. Soak the egg in plain water for two days, continue recording observations each day.

 

  1. Measure the circumference of the egg (instructions to follow at the end of the experiment).

 

  1. Soak the egg in water with food coloring (use different colors for different groups) for two days, continue recording observations each day.

 

7.  Measure the circumference of the egg (instructions to follow at the end of the

     experiment).

 

8.  Soak the egg in salt water for two days, continue recording observations each day.

 

  1. Measure the circumference of the egg (instructions to follow at the end of the

experiment).

 

  1. Soak the egg in carbonated beverages (use different colors for different groups) continue recording observations each day.

 

11. Measure the circumference of the egg (instructions to follow at the end of the

      experiment).

         

     

HELPFUL HINTS:

 

Follow these steps when measuring the egg each day:

 

  1. Carefully take the egg out of the liquid and pour the liquid down the drain.

 

  1. Rinse off the egg in cold water over the sink and blot it dry with a paper towel.

 

 

  1. Using a flexible tape measure or a piece of string, measuring the circumference of the egg.  If you are measuring your egg with a piece of string, follow these steps:

 

    1. Wrap the string snugly around the egg at the equator, (but be careful not to cut into the egg’s membrane with the string).
    2. Grasp the string between your thumb and finger exactly at the point where the end of the string meets the rest of the string after circling the egg.
    3. Keeping your thumb and finger in place, lay the string straight on a flat surface.
    4. Use a metric ruler to measure the distance from the end of the string to the point where you are holding it.
  1. Record your measurements and any other observations about the egg in the data table

     on Worksheet 1 or in a similar data table or one of your own.

 

  1. Return your egg to the container and cover it with the same or another liquid, according

     to the procedure above.